Apply texture to plane via script
The texture script there still works in 2.73, but there are a couple points that you may need to check.


Render engine needs to be set to Blender Render, the sample script is not setup to work with cycles.
The viewport shading settings. The texture will not show if the viewport is displayed in solid shading. In Textured shading you also need to enable GLSL instead of the default Multitexture. In Material shading the texture will show. These options will only show the image part of the texture, you will only see the full result of the texture in rendered display of the viewport or if you render an image (F12).


The Viewport shading mode can be found in the header of the 3dview -



GLSL shading can be enabled in the Shading panel of the properties sidebar (press N) -



If you want to adjust the script to work with cycles this question might get you started.